Personally, I don't think creationism should be taught in public schools (assuming it's not a religious school). Creationism, as you mentioned, isn't a theory, it's a myth. When I say myth, I am referring to a traditional story not a false belief. With no proper evidence to support Creationism, there isn't a proper way to teach it in a classroom. Why would we teach our children something that we can't prove or have evidence of? Living in the Bible Belt, I know that almost everybody here is a Christian. My problem isn't that people here are religious, or even that they didn't teach us about evolution. My problem is that they didn't teach us evolution until 10th grade. Evolution should be taught like any other material at school. You start out at a younger age and you teach the basics, but as they progress through school, you add on to those basics.
Anyway, those are my thoughts.